Timing Off Runs Bad

[ZNate]

I tried getting spark from both ends of the coil wire on the chance I was doing it wrong, but still no spark.  

The entire ignition was new (Pertronix, rotor, cap, 3.0 Ohm Flamethrower coil) 1500 miles ago, except for the albatross distributor.

[Zed Head]

Bummer.  Could be that you just lost a connection somewhere.  Get out your meter.  Don't overlook grounds.  

The Ignitor I is susceptible to overheating if the key is left on too long.  Hopefully that's not what happened.

https://images.carid.com/pertronix/products/pdf/1183-installation-instructions.pdf

"2. Leaving the ignition “ON” with the engine “OFF” for an extended period could result in permanent damage to the Ignitor."

[Zed Head]

I found a test method for the module itself on Summit Racing's site.  Worth reading...

https://static.summitracing.com/global/images/instructions/pnx ignitor i tests.pdf

[ZNate]

Read about the downsides of Pertronix version 1, so I have been careful about leaving the key ON.  Let me dig up some alligator clips and I'll test the module.  Not sure if I can get the test completed tonight or tomorrow morning.

[Zed Head]

You can see by their diagram that the module grounds through the distributor body and the mounting screws to get to the engine block and complete the circuit .  Might be that by loosening all of the various mounting bolts you lost your ground.  Attach a wire directly from the distributor body if you want to be sure the module has a good ground.  It's actually the most important one for spark strength.

[ZNate]

Zed Head: Thank you for the testing information.

Performed the test and power is constant.  Also did the test with the cap on, with same results.  So it looks like the module has quit.

The photo shows my rigged up test and meter reading.  I can think of two instances where it may have been damaged. 
1. I did a test drive to adjust timing with the new carbs.  I pulled to the road side and turned on my flashers, which caused my amp meter to go wild.  It then blew the 20 amp fuse.
2. After the flashers quit, I drove home and used the right turn signal, which caused the engine to die. Got it restarted, but had no gauges or brake lights on the drive home.  Another 20 amp fuse blew.

Never had fuse problems before.  After replacing the fuses, the flashers and turn signals work fine.  FYI, I have cleaned up all my switches in the past couple years (2K miles), so they should be fine.

So where does this leave me?
1. Purchase another Pertronix version 1 or,
2. Purchase stock 240Z distributor and install Pertronix or,
3. Purchase a stock 280ZX distributor, which includes electronic ignition.  Part stores have rebuilt units for about $160.

I guess I can do more research, but these are some questions I would need to answer too:
Will my current rotor and cap fit these different distributors?

My current Pertronix set-up bypasses the ballast resistor and uses a 3 Ohm coil.  Will I need to install a stock coil and hook up the ballast resistor?

[SteveJ]

With the 280ZX distributor you will need to buy a 280ZX distributor mount and timing plate. The mounting bracket seems to be pretty rare now, and it's not like they were very common 10 years ago when I last bought one. (People seem to forget about this when they suggest a 240Z owner swap to the ZX distributor.)

A 240Z distributor with Pertronix would probably fit in the mount you have now. By the way, Summit Racing seems to have the best price around on the Pertronix right now.

I'm not sure what part number Pertronix you would need for the Mallory. Looking at their website, this was the only 6 cylinder, 12VDC, negative ground Mallory kit I saw: https://pertronixbrands.com/products/pertronix-ml-161-ignitor-mallory-6-cyl

[Zed Head]

I forgot who made the universal base plates for the distributors.  They're a member.  That opens up options.

For what it's worth, the brand name "Mallory" doesn't mean much for what you're trying to do.  It might have some collection value, if it is an actual Mallory-made product from the past.  But really, it's two advance mechanisms and a way to distribute the spark.  Many ways to get that done.

You might put a set of points back in while you're thinking.  Then you can get on with carb tuning.  Points work pretty well, they've been around for years.

[Zed Head]

Found it.  @zKars

 

[ZNate]

Since my Mallory specific Pertronix failed, I am going to install an original 240Z dizzy.  Should have it in a few days.  Probably going to purchase a newer version of Pertronix and the OEM type cap and rotor.  Do not think the Mallory parts will work on the OEM unit.

Will provide and update when I get my parts.

Thank you!

[ZNate]

Still no luck…

Since my last post on July 17, I have completed the following:
1. Installed clean, used 240Z distributor.
2. Installed Pertronix Ignitor II, plus new cap and rotor.
3. Reset oil pump shaft to 11:25 position at TDC, previously it was a notch off.
4. Installed vacuum line to #1 carb.

At TDC, the rotor now points just below the 9 o’clock position.  While cranking the starter, there is ignition firing that “blows back” and slows or bogs down the starter.

Do I have the distributor installed 180 degrees off?  I used a small rubber plug to locate the compression stroke for TDC.  When it popped off, I used that location for aligning TDC.
 

[ZNate]

Got it!

Distributor was too far advanced.  Had the distributor set to the mid-point marker, but turned it full retard to start the engine.

Runs pretty smooth at 1100 rpm, but now I need to set the timing and fine tune the new ZTherapy carbs.

Thank you for all your help!

Nate